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Fencer Vulns
high 7.8

CVE-2026-65704 json

FFmpeg 8.1.2 Out-of-Bounds Write via TY Demuxer and Shorten Decoder

published 2026-07-23 3 mo ago modified 2026-08-08 3 mo ago also EUVD-2026-48371 , GHSA-98cx-cw6c-5pj4 , JLSEC-2026-1179

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 7%
public exploits
0
none known

Summary

FFmpeg through 8.1.2 contains an out-of-bounds write vulnerability that allows attackers to cause heap corruption by supplying a crafted ffconcat file processed with the -safe 0 flag. The TY demuxer's demux_audio() function decrements packet size without bounds checking, producing a negative size value that is passed to memcpy() in shorten_decode_frame(), where conversion to size_t wraps the value to near SIZE_MAX and triggers reads beyond the source allocation and writes far beyond the Shorten decoder's bitstream buffer.

Patch / fix

  • julia FFMPEG_jll 9.0.0+0
  • julia FFMPEG_nogpl_jll 9.0.0+0
  • julia FFplay_jll 9.0.0+0
  • ffmpeg Debian 14 7:9.0.2-1

debian advisories DEBIAN-CVE-2026-65704

  • ffmpeg Ubuntu Pro 20.04 LTS 7:4.2.7-0ubuntu0.1+esm16
  • ffmpeg Ubuntu Pro 22.04 LTS 7:4.4.2-0ubuntu0.22.04.1+esm15
  • ffmpeg Ubuntu Pro 24.04 LTS 7:6.1.1-3ubuntu5+esm13
  • ffmpeg Ubuntu Pro 26.04 LTS 7:8.0.1-3ubuntu2+esm4

ubuntu advisories UBUNTU-CVE-2026-65704

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • ffmpeg-4 SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +1 more 4.4.8-150400.3.75.1
  • ffmpeg-4 SLE Workstation Extension 15 SP7, SLE Module for Package Hub 15 SP7 4.4.8-150600.13.55.1

suse advisories SUSE-SU-2026:4150-1SUSE-SU-2026:4149-1

  • ffmpeg-7 openSUSE Leap 16.0 7.1.5-160000.1.1
  • ffmpeg-8 openSUSE Tumbleweed 8.1.2-3.1
  • ffmpeg-7 openSUSE Tumbleweed 7.1.5-2.1
  • ffmpeg-4 openSUSE Tumbleweed 4.4.8-4.1
  • ffmpeg-9 openSUSE Tumbleweed 9.0.1-2.1

opensuse advisories openSUSE-SU-2026:21877-1openSUSE-SU-2026:11682-1openSUSE-SU-2026:11665-1openSUSE-SU-2026:11563-1openSUSE-SU-2026:11545-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-65704 updated cvss 5.5

ffmpeg: FFmpeg: Heap corruption via crafted ffconcat file can lead to arbitrary code execution

  • Red Hat Enterprise Linux AI (RHEL AI) 3 ffmpeg, rhelai3/bootc-cuda-rhel9, rhelai3/bootc-rocm-rhel9, rhelai3/bootc-aws-cuda-rhel9, rhelai3/bootc-gcp-cuda-rhel9, rhelai3/bootc-azure-cuda-rhel9, +1 more Red Hat OpenShift AI (RHOAI) rhoai/odh-vllm-gaudi-rhel9
    affected: no fix available “Fix deferred”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
3 mo ago

Exploit prediction

0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 7.3 CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CNA 4.0 7.3 CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
OSV 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
julia FFMPEG_jll
<9.0.0+0
9.0.0+0
julia FFMPEG_nogpl_jll
<9.0.0+0
9.0.0+0
julia FFplay_jll
<9.0.0+0
9.0.0+0

Affected products

  • FFmpeg FFmpeg

Classification

Weakness
  • CWE-787 Out-of-bounds Write
  • CWE-191 Integer Underflow (Wrap or Wraparound)

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.